Adaptive Multicarrier OFDM SAR Signal Processing

This paper describes a solution algorithm for ultrawideband orthogonal frequency-division multiplexing (OFDM) synthetic aperture radar (SAR) signal processing. A single pointlike target is assumed, and stripmap SAR geometry is used for the analysis. The peculiarity of extracting phase history from a multicarrier return signal-such as OFDM-is in solving for the phase component using all signals' subbands in frequency domain. The least squares approach is used to find the solution form, and a grid search algorithm is used to find the phase history sample estimates. Simulation results illustrating the algorithm's performance in a 1-D cross-range profile reconstruction case, as well as in 2-D SAR imaging scenarios, are presented and discussed. It is shown that the proposed method is effective in reconstructing cross-range profiles and possesses high potential for adaptive SAR imaging while exhibiting good computational performance approximating that of range-Doppler algorithm.